The present invention relates to a lock status indicator for a key fob used for remotely locking and unlocking a vehicle door that informs the user for a limited period of time after having left the vicinity of the vehicle whether the door lock button had been depressed to actuate the door lock.
The use of key fobs for remotely locking and unlocking vehicle doors has become almost universal. In its simplest form the key fob is a hand held device having a depressable button labeled “lock” or some similar label, and another depressable button labeled “unlock” or some similar label. Located within the key fob are the electronics and power source required to transmit a signal via a modulated radio frequency or via infrared to a receiver communicating with the lock/unlock mechanism of a door or doors of a vehicle upon depression of the “lock” or “unlock” button. Additional buttons, such as a “panic” button for activating the vehicle's horn as an alarm, may also be present.
After parking a vehicle and walking away to perform an errand, or for other reasons, a user may not remember whether the vehicle's door was locked at the time of departure by having depressed the “lock” button of the key fob. Rather than having to walk back towards the vehicle into a proximity where the lock button can be depressed to insure activation of the door lock, it would be desirable to have some indicator means associated with the fob itself to inform the user as to whether the lock button had indeed been depressed upon departing the vehicle.
There have been several suggestions in the prior art for ways for a key fob to indicate the status of a door lock. Most are complex and expensive, involving electronic communication between a sensor in the door and a receiver in the fob. See, for example, U.S. Pat. No. 8,362,898.